Mars + Viper

Why this works

Trapping enemies in Arena of Blood for Viper to melt sounds good on paper, but it rarely works out. Viper's damage comes from sustained, single-target attacks and damage-over-time effects. He can't provide the massive area-of-effect burst that Mars needs to wipe a team inside his ultimate. While Nethertoxin can be placed inside the Arena, enemies are not forced to stand in it and will simply move away from the small circle. The two heroes' area denial abilities don't stack effectively, leading to wasted potential during crucial teamfights.

In a real engagement, Mars will trap several heroes, but Viper can only focus one. The others are free to attack Mars or wait out the ultimate's duration, as Viper's damage isn't fast enough to be a major threat to everyone at once. Both Mars and Viper often want to be the team's mid-game tempo-setter, creating space and pressure. When on the same team, their roles can feel redundant. They don't amplify each other's strengths, and the lineup can lack the focused burst or late-game scaling needed to close out games.